I'd recommend a cruiser first. Don't be fooled by the name, it's just a 24" bmx. Nothing cruiser about them. People get into bmx when they are small and learn the dynamics of an extremely agile 20" bike. At 250 and 6 feet, you don't sound 12 years old. Start on a 24" and if you have fun in the dirt there will ALWAYS be a guy on a 20 who will wanna try your ride out and swap for 5-10 minutes. Jumping a 24 is far more forgiving for someone "new" to bmx. You might keep your teeth in your head better this way. A 24 won't dead sailor as bad.

Graduate to 20" later.